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Colour-vision-safe palette

Source: R/plots-design.R
cr_palette.Rd

Returns hex colours from the palette every cr_plot_* function uses for discrete groupings. The qualitative set is Okabe-Ito, the standard colour-vision-safe qualitative palette; it deliberately contains no red/green pair, so hue never encodes an opposition that a large minority of readers cannot separate.

Usage

cr_palette(
  n = NULL,
  type = c("qualitative", "sequential", "diverging"),
  names = NULL
)

Arguments

n

Number of colours to return. NULL (default) returns the whole palette: 8 colours for "qualitative", 256 for the continuous types. Requesting more than 8 qualitative colours interpolates between the anchors and warns, because the result is no longer guaranteed to be colour-vision-safe; prefer facetting over more than 8 hues.

type

One of "qualitative" (discrete groups), "sequential" (one-directional magnitude) or "diverging" (signed magnitude around a meaningful zero, ramped blue-to-vermillion rather than blue-to-red-green).

names

Optional character vector of names to attach to the returned colours, for use as the values argument of a manual scale. Must have the same length as the result.

Value

A character vector of hex colour strings, named when names is supplied or when the whole qualitative palette is returned.

Details

Hue alone is not treated as a sufficient encoding: use cr_shapes() (or cr_scale_group(), which wires both at once) so that every grouping is carried by shape as well as colour.

See also

cr_shapes(), cr_scale_group(), cr_theme()

Other plot design: cr_scale_group(), cr_shapes(), cr_theme()

Examples

cr_palette()
#>           blue     vermillion   bluish_green         orange reddish_purple 
#>      "#0072B2"      "#D55E00"      "#009E73"      "#E69F00"      "#CC79A7" 
#>       sky_blue         yellow           grey 
#>      "#56B4E9"      "#F0E442"      "#999999" 
cr_palette(3)
#>         blue   vermillion bluish_green 
#>    "#0072B2"    "#D55E00"    "#009E73" 
cr_palette(5, names = c("a", "b", "c", "d", "e"))
#>         a         b         c         d         e 
#> "#0072B2" "#D55E00" "#009E73" "#E69F00" "#CC79A7" 
cr_palette(7, type = "diverging")
#> [1] "#0072B2" "#70A8CF" "#B5D5E6" "#F7F7F7" "#F8C0A8" "#EC8D5C" "#D55E00"